Vehicle lift



June 9, 1942. P 1 KROLL 2,285,989

VEHICLE LIFT Filed April 4, 1941 4 Sheets-Sheet l wn QM, ow ON ww 3 SASJune 9, 1942. P. J. KROLL 2,285,989

VEHICLE ,LIFT

Filed April 4, 1941 4 Sheets-Sheet 2 June 9, 1942. P, 1 KROLL 2,285,989

VEHICLE LIFT Filed April 4, 1941 4 Sheets-Sheet 3 g l 'ff-M "T"- :I gg,

P. J. KROLL VEHICLE LIFT June 9, 1942.

4 sheets-sheet 4 Filed April 4. 1941 uw E ww Patented June 9, 1.942

VEHICLE LIFT Philip J; Kroll, New Orleans, La., assigner to MarjorieKroll, Cambridge, Mass.

Application April 4, 1941, serial No. 386,952

(ci esi-ss) 27 Claims.y

This invention relates to vehicle lifts and` is an improvement over thestructures shown in my prior Patents Nos. 2,199,524, granted May 7, 1940and 2,231,362, granted February 1l, 1941.

There are two well known types of vehicle lifts in common use in motorvehicle service stations, namely, the "run-on type and the free-wheel"type.. In the first mentioned type runways are provided for the vehiclewheels so that the vehicle may be driven onto the lift, whereupon thelift may be elevated and the vehicle will be supported by the wheelsthereof. The freewheel type of lift provides parallel rails engageablebeneath the axles of the vehicle to support the vehicle when the lift iselevated.

Each type of lift is advantageous for performing different types of workon a vehicle, but it involves too great an expense and the taking up oftoo much space in a service station to purchase and install a vehiclelift of each type. Moreover, many service stations equipped withfree-wheel lifts find such lifts decreasing in usefulness because of theincreasing number of motor vehicles provided with individual wheelsuspension which renders it impracticable for them to be elevated on afree-wheel lift.

In my prior patents referred to I have disclosed two different types ofapparatus adapted for use with free-wheel lifts to adapt such lifts foruse as run-on lifts, the apparatus being supported on the rails of thelift and providing means for supporting the vehicle through the l wheelsthereof. Such prior structures, therefore, provide effective means forconverting a freewheel lift into a run on lift, thus adapting a singlelift in a service station to any use to which a lift may be put andeliminating the necessity for the purchase and installation of twodifferent lifts. The prior structures include two wheel supportingdevices, one for the front wheels of the vehicle and the other for therear vehicle wheels. Both of the wheel supporting devices are readilydetachable, and in use, the rear wheel supporting device is fixedagainst longitudinal movement with respect to the rails and the twodevices are normally locked to each other so that when a vehicle isbeing driven into position, the front vehicle wheels may roll over therear wheel supporting device and then into position on the iront wheelsupporting device, whereupon lthe two devices are disconnected from eachother and the further movement of the vehicle forwardly onto theapparatus .causes the front wheel supporting device to move with the`front vehicle wheels until the rear wheels reach their proper positiononi/the rear wheel supporting device. Both of the wheel supportingdevices are provided with means for chocking the vehicle wheels toprevent rolling movement of the vehicle. When it is desired to removethe vehicle, the lift is lowered and the vehicle is backed off from theapparatus, the rear wheels moving from the rear wheel supporting devicewhile the front wheel supporting device moves rearwardly and returns toits interlocking relationship with respect to the rear wheel supportingdevice, whereupon the front wheels of the vehicle roll from the frontwheel supporting device over the rear wheel supporting device and thencecompletely from the latter device.

The apparatus forming the subject matter of the present invention hasfor its principal object,I generally speaking, the provision of anapparatus for converting a free wheel lift into a run on lift whereinall of the advantages of the prior structure referred to are retained,but wherein other advantages are introduced, particularly with relationto the simplification of the mechanism, the reduction of the number ofparts involved, and the reducing of the cost of manufacture of theapparatus.

A further object is to provide an apparatus of the` character referredto wherein the chocking means for the rear vehicle wheels and theinterlocking means for connecting the two supporting wheel structures toeach other have been materially improved and simplified.

A further object is to provide a simplified rear wheel chocking meanswhereim the elements which turn to an angular position forwardly of therear wheels of the vehicle are arranged so that their front ends turnupwardly as distinguished from the prior constructions referred to, andwherein such turning motion is utilized in a simple and eifective mannerfor securing and releasing the two wheel supporting structures withrelation to each other.

A further object is to provide an apparatus of the character referred towherein the rear wheel supporting structure possesses the advantages ofthe long ramp means' of my prior Patent No. 2,231,362, but which isadvantageous thereover for the reason that when the lift is elevatedwith a vehicle thereon, a substantial portion of the rear end of eachramp drops downwardly to an inoperative position, thus avoiding anyinterference with the entrance of a meA chanic between the rear ends ofthe lift rails to perform work on the vehicle.

A further object is to provide a vehicle lift converting mechanism ofthe type referred to wherein the adjacent chocking elements of the frontand rear wheel supporting devices directly engage each other to locksaid devices against movement away from each other while the vehicle isbeing driven onto or off from the lift.

A further object is to providea front wheel supporting vdevice havingrubber tired rather than metal supporting wheels to avoid abrasion andinjury to the concrete supporting surfaces on which such device rollswhile a vehicle :is being moved onto or oi from the apparatus, and toprovide in connection therewith eective means for supporting the rearend of the front wheel supporting device with respect to the surroundingsurface to prevent any interference with any parts of the apparatusincidentl to downward movement of the front wheel supporting device bythe deforming of the rubber tires under the weight of a vehicle on thelift.

'Other objects and advantages of the invention will become apparentduring'the course of the following description. r

In the drawings I have shown one embodiment of the invention. In thisshowing: l

Figure 1 is a side elevation of the apparatus with the parts inoperative position to support a vehicle through the wheels thereof,parts beirig broken away,

Figure 2 is an enlarged side elevation showing the parts in normalpositions with the front and rear supporting devices or units ininterlocked relationship,

Figure 3 is a plan view of the apparatus,

Figure 4 is an enlarged transverse sectional view on line 4-4 of Figurel,

Figure 5 is a similar view on line 5-5 of Figure 1, y

Figure 6 is an enlarged vertical longitudinal sectional view on line 6 6of Figure 3 showing the two wheel supporting units in interlockingrelationship as in Figure 2,

Figure '7 is a detail perspective view of one of the front wheelchockelements, and,

Figure Sis a detail sectional view on line 8-8 of Figure 3. f'

Referring. to Figures lto 6 inclusive,' the numeral II) designates aconventional freewheel" automobile lift'comprising parallelrails IIshown as being rigidly connected by a plate I2 carried on the upper endof the lift plunger I3. These elements have not been illustrated inparticular detail since they are conventional and form no part per se ofthe present invention.

The apparatus forming the subject matter of the present invention, to bedescribed below, is eliminated from the lift structure when the latteris to be used as a "free-wheel lift, in which case the vehicle, isdriven into position over the rails Il, whereupon the lift is elevatedand the rails II engage the axles of .the vehicle to elevate it.

The present invention provides means for converting the free-wheel liftinto a run on lift and comprises front and rear wheel supportingstructures respectively indicated as a whole by the numerals I4 and I5.The front wheelsupporting structure is in the form of a wheeled dollyand comprises a transverse supporting beam I6, which may be of channeledstructure as shown in Figure 6.v The central portion of the beam I6extends transversely of the rails II and is normally spaced thereaboveas clearly shown in Figure 4. outwardly of the rails II,

the supporting beam I6 extends downwardly at Cil an angle as at i1(Figure 4) and thence outwardly horizontally/as at. I8 to carry thesupporting structure for each of the front wheels.

Since these two structures are identical, only one need be described 'indetail.

. Each front wheel supporting device .has been illustrated as a whole bythe numeral I9 and each comprises a pair of parallel supporting siderails 20 which may be formed of a single strip of ma# terial bent insubstantially U-shape and connected at their rear ends as at 2I (Figure6). The supporting side rails 20 carry spaced axles 22 on each of whichis arranged a supporting Wheel 23 preferably provided with a rubber tire24 the purpose of which will be referred to later. Adjacent its rearend, each rail 20 is provided with an upstanding member 25 and thesememlbers are connected at their upper ends by an integral cross member26 inclined from the horizontal as in Figure for a purpose to bedescribed. The upstanding members 25 may be Welded to or formed integralwith the respective side rails 2U. These side rails are suitably securedto the supporting beam I6. For example, referring to Figure 6, the siderails 20 may be notched as at 21 to receive the adjacent flanges of theend horizontal portion I8 of the beam I6, and such flanges may be weldedto the side rails. 25 to rigidly connect the latter to the supportingbeam I E.

An invertedl substantially T-shaped cross member 23 is welded orotherwise secured to the side rails 20 (Figures 3 and 6) and projects asubstantial distance onopposite sides of the side rails 29. This crossmember is provided at its ends with upstanding bearing ears 29 carryingpivot pins 3U. A combined ramp andl runway element 3| is arranged overthe cross member 23 and is provided with downturned parallel sideflanges 32 through which the pivot pins 3l) extend to pivotally supportthe member 3|. At their left hand or forward ends, the anges 32 aretapered as at 33 to decrease in width to permit the member lto swingdownwardly to the .Y tionary chock member 35. The chock member dottedline position shown in Figure 6, as ywill be obvious. Centrally of itswidth, the rear end of .the member 3I is provided with a downturned lip34 for a purpose to be described.

As will become obvious the front wheel of a motor vehicle is adapted toroll over the ramp member 3| of each front wheel device I9, whereuponitcomes to rest against a -curved sta- 6, lis provided with a relativelysmall wheel 39 mounted on an axle 40 extending through the side rails20. This wheel is preferably steel and arranged somewhat above the planeof the bottoms of the wheels 23, and is provided for a purpose to bedescribed.

The rear wheel supporting structure comprises a transverse supportingbeam 4I, which also may be -of inverted channel cross section similar tothe beam I6. However, the beam 4I occupies the normal position shown-in` Figure 5, resting upon and supported by the tops of the lift railsIl. It will become apparent that the beam I8 is normally spaced abovethe rails |I to permit the structure to be movable with the front wheelsoi' thevehicle. while the beam 4| seats upon the rails4 II for thereason that the structure I is normally nxed against movementlongitudinally of the rails Il. Toprevent such movement of the structure|5, the beam 4I is provided with angle brackets 42 which'may be weldedto the beam 4|, and these brackets are provided with openings 48 toselectively receive pins 44 (Figures 3 and 8) receivable in openings 45formed in the upper ilanges of the rails Outwardly of the rails the beam4| slopes downwardly as at 45 and terminates in horizontal end portions41 each of which carries a rear wheel supporting structure indicated asa whole by the numeral 48. The structures 49 are identical andaccordingly only one need be described in detail. Each of thesestructures comprises inner and outer parallel side frame members 49 and50 shown in plan in dotted lines in Figure 3. The rail 59 is providedadJacent its forward end, that is, the left hand end as viewed in Figure3, with a pivot pin 5| and in axial alignment with such pin, the siderail 49 carries a similar pivot pin 52. These pins are carried byupstanding ears 53 formed integral with the two side rails andillustrated in Figures l, 2 and 6.

Adjacent the ear 58 of the rail 50, the latter rail is turned inwardlyto form an angularly extending portion 54, the extremity of which iswelded at the point 55 (to the adjacent horizontal portion 11 of thebeam 4|). The rail 49 extends to the left, as viewed in Figure 3, beyondits ear 53 to form an extended portion 55. The material of the rail isthen extended transversely and to the right to form a portion 51parallel to the portion 56, and thence the rail extends at an angle asat 58 in the same manner as the portion 54 of the rail 50, and is weldedat the point 59 to the beam portion 41. Between the parallel railportions 55 and 51 is arranged a wheel 50 rotatably supported by suchparallel rail portion upon an axle 5|. This wheel, of course, is carriedby each of the rear wheel supporting units and the two wheelsare adaptedto form rollers to support the unit I5 as a whole when the latter ismoved into its normal position in a manner to be described.

The portion of the rail 49 to the left of the pivot pin 52 is arrangedat an inclineas at 52 (Figure 6) to permit the opposite end of the unitI5 to be tilted to rest on the wheels 50. From the point at which therail portion 58 reaches the ground level, that is, from the point 53(Figure 6) it slopes upwardly as at 54 to the point 59 at which it iswelded to the beam portion 41. This is likewise true in the lower edgeof the portion 54 of the rail 55, and to the bottoms of these inclinedportions of the rail portions 54 and 58 there is welded a plate 55(Figure 6) the right hand end of which is welded at the point 55 to thebeam portion 41. Accordingly it will be apparent that the two rails 49and 59 and the plate 55 are rigidly fixed to each other and to the beamportion 41. Referring to Figure 6 it also will be noted that the rails49 and 50 are slotted as at 51 to receive the ilanges of the beamportion 41 and are preferably welded thereto to assist in forming arigid structure.

IThe ears 53 carry the pivot pins 5| and 52, as previously stated, andthese pins plvotally support a ramp plate 68 by extending throughdownturned anges 59 formed on the edges thereof. The two structures I4and I5 normally occupy the interlocked relationship shown in Figure 6under which conditions the portion of the ramp plate 58 to the right ofthe pivots 5I and 52 rests upon the cross member 25 of the movable unitI4. As viewed in Figure 6, the ramp plate 58 has its top slopingupwardly from the` right hand end thereof to a point spaced from theleft hand end of the ramp plate, at which point the rampplate isprovided with an opening 10 which normally receives the downturned lip34. In the interlocked position of the parts, the ramp plate 3| isapproximately horizontal, and the same is true of that portion of theramp plate 58 which lies beneath the ramp plate 3|. f

'I'he ramp plate 58 is shown in perspective in Figure 7 of the drawings,and it will be noted that the side flanges of this plate to the left ofthe opening 1U converge toward each other. Similarly, the flanges 33 ofthe ramp plate 3| diverge toward their` right hand ends as viewed inFigures 3 and 6, and this arrangement is provided to insure the entranceof the left hand end of the ramp plate 58 within the ramp plate 3| whenthe latter moves toward its interlocking position in a manner to bedescribed. As shown in Figures 6 and 7, the left hand end of the rampplate 56 is provided with a pair of feet 1|, Welded to the adjacent endsof the flanges 59 and sloping downwardly and to the left. The lower endsof these feet, as shown in Figure 6 are'engageable against the top ofoneside of the base flange of the cross member 28 to limit turningmovement of the ramp plate 68 in a counter-clockwise direction under theweight of a vehicle passing thereover. A tension spring 12 is connectedbetween one of the flanges 59 (Figure 6) and a portion of the side railstructure 49, preferably the portion 51, to tend to resist turningmovement of the ramp plate 58 when the two units |4 and I5 aredisconnected from each other.

Each rear wheel supporting unit 48 further comprises a ramp section 13the left hand end of which, in the normal position of the parts,overlaps the right hand end of the ramp plate 58 as shown in Figure 6.Referring to Figure 5 it will be noted that the outer edge of the rampsection 13 is turned downwardly to form a depending flange 14 while theopposite side is turned upwardly to form anupstanding flange 15. Thelatter flange is turned upwardly for two reasons, namely, to avoid thebeam 4I and to provide a guide for the wheels of a vehicle passingthereover. The depending flange 14 is provided adjacent its right handend as viewed in Figure 1 with a pivot pin 15 which passes through theadjacent end of the side rail 59. The opposite side of the ramp section13 is provided with a depending ear 11 through which extends a similarpivot pin 18, and this pin also extends through the side rail 49. Thepivot pins 15 and 18 are arranged in axial alignment and accordinglypivotally support the ramp section 15. To one side of one of the slopingside rail portions 54 or 58 (Figure 3) an eye 19 is carried by the rampsection 13 and a chain 80 (Figure 6) is connected between this eye and asimilar eye 8| carried by the adjacent side rail, such as the side rail49 as indicated in Figure 3. This chain limits upward movement of thefree end of the ramp section 13 and thus prevents upward movement of theadjacent end ofthe from adjacent the ramp section 18.

An entrance ramp 82 is pivoted to the pivot.

pins 18 and 18. As is true of the ramp section v18,v the entrance ramphas one edge turned to form a dependent flange 88 while the opposite orinner edge is turned to form an 'upstanding flange 84 substantiallyaligned with the flange 15 in the normal position of the parts to assistin guiding the front wheels of an entering vehicle. The depending flange83 (as shown in Figure 5) receives the pivot pin 16, while the pivot pin18 is received in a projecting earkmember 85 welded or otherwise securedto the ramp section 82. The inner ends of the pivot ear 86 and of theflange 83 are formed with similarly sloped inner ends 88 so that whenthe entrance ramp drops downwardly to the position shown in dotted linesin Figure l turning movement of the entrance ramp will be limited byengagement of the edges 85 beneath the ramp section 13.

The entrance ramp 82 slopes downwardly in alignment with the'rampsection 13 when the parts are in the normal position shown in Figure 2.The lower or rear end of the entrance ramp carries a horizontallyextending bar 81 forming an axle to receive wheels 88 and 88. From thewheel 88 the bar 81 extends vertically as at 80, then rearwardly at anangle as at 8l, to form a handle, thence downwardly as at 82 to besecured in any suitable manner to the entrance ramp 82. The upstandingiiange 84 extends only from the vertical portion 92 of the handle 8l tothe pivoted end of the entrance ramp, and the remaining portion of theentrance ramp which lotherwise would form a portion of the :flange 84 isextended horizontally as at 83 (Figure 5) to form a wider entering endon the entrance ramp.

The operation of the apparatus is as follows:

As previously stated, the lift including the rails Il, without the unitsI4 and I5 thereon, constitutes a conventional free wheel lift which isengageable beneath the axles of a motor vehicle to elevate it, leavingthe wheels of the vehicle free. The present apparatus is the rampsection, by substantially supporting v the weight of the free endthereof. As the unit, Il is moved toward the position shown in Figure.6, therefore, the parts of the unit I 5 which co operate with andengage parts' of the unit I4 -will be approximately in the necessarypositions for the interlocking of the twounits. The right hand end ofthe ramp plate 8| (Figure 6) will be manually held approximately in thedotted line position shown in Figure 6 to pass over the top of theadjacent end of the ramp plate 68 as the unit I4 is moved towardoperative position. 'I'he left hand end of the ramp plate 68 will beheld by thel spring 12 in such a position as to' clear the adjacent baseof the cross member 28 so as to move to the relative position shown inFigure 6.

When the feet 1I are positioned as shown in Figure Gthe ramp plate 3lwill be released and since its greater weight is to the right of itspivot axis, the flange 34 will move downwardly into the opening 16. Whenthis position of the parts isnreached, it will be obvious that the crossmem-` ber 26 (Figure 6) will be in contact with the lower face of theramp plate 68 to prevent downward movement of the right hand end of thisplate. Similarly, the roller 38 will occupy its normal position engagingthe inclined plate 55 and the lower end of this plate normally is iniirm contact with the surrounding surface, which is preferably aconcrete oor.

It will be apparent that the foregoing operations may be completed, in avery brief time,

adapted to quickly and easily convert the lift into a run-on" lift.

When it is desired to convert the lift into aV run on lift, the operatorwill grasp the handles 8l and lift the adjacent end of the unit I5,whereupon the opposite end ofthe unit I5 will be sup-A ported on thewheels 60. The operator then may wheel the unit I5 after the manner of awheelbarrow, and will approach the right hand end of the lift as viewedin Figure 3 and move the unit I5 longitudinally of the rails II. 'I'heunit I5 will be maneuvered until the pins 44 (Figures 3, 5 and 8) areover the openings 45, whereupon the operator will lower the raised endof the unit I5 until the rollers 88 ancil 88 rest upon the ground, thepins 44 entering the openings 45 during such operation. It will beapparent that the unit I5 will now be xed against all movements withrespect to the rails II except upward vertical' movement, the weight ofthe unit, of course, preventing any upward movement thereof.

The unit I4 will now be moved into position from the opposite end of thelift. The elements of the unit I5, when placed in the position` referredto, will approximately occupy the normal positions shown in Figure 6,the spring 12 tending to hold the right hand end of the ramp plate 68 ina position approximately in alignment with after which the apparatus -isoperative as a runon lift. In so using'the apparatus, the vehicle willbe driven onto the apparatus from the right hand end thereof as viewedin Figures 1, 2, 3 and 6, and it will be obvious that the front wheelsof the vehicle readily may roll from the surrounding surface onto thelower ends of the entrance ramps 82. From these ramps the vehicle frontwheels will roll o ver the ramp sections 13 and since the free ends ofthese ramp sections are supported by the adjacent ends of the rampplates 68 which, in turn, are supported by the cross members 25, wheels38 and inclined plates 65, the ramp sections 13 and ramp plate 68 willremain rigidly in the positions shown in Figure 6 so that the frontiwheels may roll thereover, and thence onto the pivoted ramp plates 3l.

The front. wheels of the vehicle will then roll .across the pivoted rampplates 3l and as soon as the wheels pass beyond the axes of the pivots30, the plates 3l will start to swing toward the dotted line positionshown in Figure 6 and such position will be reached when the frontwheels of the vehicle engage the stationary chocks 35. The front wheelsof the vehicle will then be prevented from moving with respect to theunit I4 by the chocks 35 and by the pivoted plates 3|, which now act asfront wheel chocks.

Movement of the plates 3l to chocking position obviously releases theanges 34 from the aasaeso As the unit I4 moves away from the unit Il,the rear wheels of the vehicle obviously approach the unit I5 and rollover the entrance ramp 32, and thence over the ramp sections 13whereupon these elements swing downwardly to the position shown inFigure 1 and in so doing depress the adjacent edges ot the ramp platesIl to swing the latter into the inclined position shown in Figure 1. Theramp plates 68 under such conditions become checks for the rear vehiclewheels.

The lift now may be elevated to lift the vehicle through the wheelsthereof. Referring to Figure 4, it will be noted that the supportingbeam I6 -sates for any unevenness in the surrounding surface, thisfurther insuring freedom of rolling movement of the unit |4.V However,whenl` the lift is elevated movement is immediately transmitted to theunit I5 to lift it, and when the space between the beam I6 and rails |Ihas been taken up, verticalmovement. obviously will be transmitted tothe unit I4. The engagement of the beam I6 with the rails obviouslyfrictionally prevents any possibility of the movement of .he unit |4along the rails I.

As the lift moves upwardly the entrance ramps 82, which turn freelyabout the pivot pins 16 and 18 (Figures 1 and 5) swing downwardly untilthey assume the position shown in dotted lines in Figure 1, furthermovement being prevented by engagement of the edges 88 (Figure 6)against the bottoms of the respective ramp sections 13. This position isreached before the entrance ramps reach a vertical position so as tomaintain the wheels 38 and 89 in positions wherein downward movement ofthe lift and subsequent engagement of these wheels with the surroundingsurface will move the entrance ramps back toward their normal positionsas the lift is lowered. The downward swinging of the entrance ramps isprovided so as to eliminate as much as possible any interference withthe movement of mechanics around the vehicle.`

After the necessary work has been performed on the vehicle, the lift islowered and the wheels 88 and 89 of the entrance ramps contact with theground in the manner stated and are gradually swung upwardly to theirnormal positions. Such normal positions ofthe entrance ramps will bereached when the lift has been lowered to its limit of movement. Thevehicle is then started in reverse and backed off from the lift. It willbe apparent that just .before the lift reached its lower limit ofmovement the beam I6 will have become separated from the rails I I andaccordingly the unit I4 will be free to roll on the wheels 23 when thevehicle is backed of! from the lift. Rearward movement of the rearvehicle wheels takes place over the ramp section 13 until they reachpositions past the pivot axis of the ramp section 13, whereupon thesprings 12 will return the ramp plates 68 to the normal position shownin Figure 6, such movement of the ramp plates 68 lifting the free endsof the ramp section 13 until the chains 8|) limit the movement of theparts with the plates 68 and ramp section 13 in their normal positionsshown in Figure 6.

. As the vehicle continues to move rearwardly the unit I4 will approachthe unit Il and the wheels 33 (Figure 6) will engage the respectiveinclined plates 8l and move thereover until the cross members 2| engagethe beam sections 41 to limit further movement oi' the unit I4. At thistime, each cross member 26 will be in engagement with its associatedramp plate 68 to prevent downward movement of the right hand end thereofas viewed in Figure 6. Continued movement of the vehicle rearwardly willthen cause the front wheels to roll over the pivoted chock plates 3| andthese plates will be` turned by the vehicle wheels until they assume thelocking position shown in Figure 6 with theilange 34 of each plate 3| inits associated slot 10. The unit I4 will now be again placed ininterlocking relationship ready for the next operation, and the vehiclemay be entirely backed oil' from the apparatus as will be obvious.

In previous constructions, the wheels corresponding to the wheels 23 ofthe present apparatus have been made of steel and the repeated rollingof these wheels over the concrete surface with which they are incontact, with the weight of the front end of the vehicle supported bythe front wheel unit, has resulted in the abrasion and ilnally thesubstantial wearing and grooving of the concrete surface in addition torendering the operation rather noisy. The provision of the `rubber tires24 eliminates both of these dilculties.

However, the use of rubber tires 24 of suiiicient thickness to withstandsubstantial usage results in their being substantially deformed underthe weight of the front end of the vehicle when the front wheels moveinto position on the unit I4. The accompanying downward movement of theunit 4 was found'to have a tendency to disturb the normal functioning ofthe interlocking parts. For example, such downward movement causedcontact between the under side of the plates 3| and the left hand endsof the ramp plate 68 as viewed in Figure 6, thus resulting in theswinging upwardly of the right hand ends of the plate 3| sumciently todisengage the iianges 34 from the openings 10. With the presentconstruction, however, it will be apparent that the rollers 39, whichnever `contact the surrounding concrete surface, will solidly supportthe right hand end of each unit I4 by engagement with the inclinedplates .65 which, in turn, are solidly `supported .by the surroundingconcrete surface. Thus the deforming of the rubber tires cannot takeplace prior to the passage of the front wheels of a vehicle onto theplate 3|, and accordingly the deforming of the rubber tires cannot aiectthe operation of the apparatus.

From the foregoing it will be apparent that the present inventioninvolves substantial improvements over prior constructions of this typeas represented in my prior Patents Nos. 2,199,524 and 2,231,362. It isunnecessary to provide any parts specifically i'or the purpose ofinterlocking the units |4 and I5 or to provide parts specifically forthe purpose of unlocking the units when the vehicle is to be moved fromthe apparatus. The ramp plate 6B at each side of the apparatus engagesits associated pivoted chocking plate 3| to lock the two units together,and the locking and unlocking actions are performed solely through theweight of the vehicle moving onto and oif from the apparatus.Accordingly the apparatus is materially simplified and is rendered moreeasily and positively operable and at the l ing pivoted at points remotesame time the cost o production of the apparatus is quite materiallydecreased. The unit Il may be rolled into and removed from operthatitprovides for the dropping of the entrance ramps into inoperativeposition when the lift is elevated. The apparatus is'iurthercharacterized by the complete absence of complicated and expensivelocking dogs, cams, etc., as well as the complete absence of oddlyshaped openings which are relatively expensive tov produce.

It is ot be understood that the form of the invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes in the shape, size and arrangement o! parts may beresorted to without departlngfrom the spirit of the invention or thescope o! the subjolned claims.

1. Apparatus for converting a free-wheel lift, having parallelsupportinglrails, into a run- 'on" lift. comprising a pair of unitsadapted to be arranged on the supporting rails, one for sup- \portin'gthe front vehicle wheels and the other for supporting the rear vehiclewheels, one of said units having a pair oi.' ramp structures eachcomprising a pair or members having adjacent ends in cooperativerelationship and normally positioned for the passage of a vehicle wheelthereovervonto the other unit, said members be- 'ing pivoted at pointsremote from said cooperating ends whereby the latter aremovabledownwardly under the weight of a vehicle thereon underpredetermined conditions to chock the vehicle wheel thereon.

J2. Apparatus for converting a free-wheel lift,having .parallelsupporting rails, into la runon lift, comprising a pair of units adaptedto i A be arranged on the supporting rails, one :for supporting thefront vehicle wheels and the other for supporting the rear vehiclewheels, one of said units having a pair of ramp structures eachcomprising a pair of members havingl adjacent ends infcooperativerelationship land normally positioned for the passage of a vehicleAwheel thereover'onto the other unit, said members being pivotedat'points remote from said cooperating ends whereby the latter aremovable downwardly iinder the weight of a vehicle thereon under'predetermined conditions to chock the vehicle wheel thereon, and meansfor holding said members in normal position for the passage of a vehiclewheel thereover.

3. Apparatus for converting a free-wheel lift, having parallelsupporting rails, into a runon lift, comprising a pair of units adaptedto be arranged on the supporting rails, one for supporting the frontvehicle wheels and the other for supporting the rear vehicle wheels, oneof said units having a pair of ramp structures eachk comprising a pairof members having adjacent ends in cooperative relationship and normallypositioned for Lthe passage of a vehicle wheel thereover onto the otherunit, said members befr'om said cooperating ends whereby the latter aremovable downwardly under the weight of a vehicle. thereon underpredetermined conditions to chock the vehicle wheel thereon, the otherunit being movable away from the rst named unit and having a pair ofchocking members one of which is movable and normally arranged in aposition to form a. continuation of one of said pivotedl meml bers whensaid units are in adjacent relationship, said movable chock elementbeing arranged to be moved by a vehicle wheel passing thereover toassume-chocking relationship with re- K specttosuch' vehicle wheel.

4. Apparatus for conve lift, having parallel supporting rails, into a"runy on lift, comprising a pair o; units adapted to v be arrangedon'the supporting rails, one for supporting the front vehicle wheels andthe other for suppor-ting the rear vehicle wheels, one ofl said unitshaving a pair of ramp structures each comprising a pair of membershaving.adiacent ends inl cooperative `relationship and normallypositioned for the 'passage of a vehicle wheel thereover onto' theother` unit, said members being pivoted at points remote from saidcoopere ating ends whereby the latter are movable downwardlyunder theweight of a vehicle thereon under predetermined conditions to chock the,vehicle wheel thereon, means for holding said members in normalposition for the passage of a vehicle wheel thereover, the other unitbeing movable away from the rst named unit, and

means for releasing said holding means upon -movement of said other unitaway from the tlrst named unit. L

\ 5. Apparatus for having parallel supporting rails, into a run-on lift,comprising a pair of units adapted to be arranged on the supportingrails, one forsupporting the front vehicle wheels and the other forsupporting the rear vehicle wheels, one of said units having a pair oframp structures each comprising (a pair of members having adjacent endsin cooperative relationship and normally positioned for the passage of avehicle wheel thereover ontothe other unit, said members being pivotedat points remote from said cooperating ends whereby the latter aremovable downwardly under the weight of a vehicle thereon underpredetermined conditions to chock the vehicle wheel thereon, the otherunit being movable away from the first named unit and having a pair ofchocking members'one of which is movable and normally arranged in aposition to forni a continuation of one of said'pivoted members whensaid units are in adjacent relationship, said movable chock elementbeing arranged to be moved by a `vehicle wheel passing thereover toassume a checking relationship with respect to such vehicle wheel, andmeans cooperating between said movable chocking member and the adjacentramp memberfor, interlocking said units with respectV fromv movingthereon and the other being mounted to move toward and away from thefirst named unit, a pair of rampstructures on the iirst named unit eachcomprising a pairof members having adjacent ends in cooperatingrelationship for the passage of a vehicle wheel thereover when saidmembers are in a normal position, and means constructed and arranged tobe operative when the second named unit is in predetermined adjacentrelationship to the rst named unit for holding the members of said pairsin normal position and for releasing the members of each of f said pairsfor downward movement adjacent their rting a.v free-wheel converting a.free-wheel lift,

means engageable with the rails to prevent it asuman adjacent ends whenthe second named unit moves away from the rst named unit and vehiclewheels are arranged on said ramp structures.

7. Apparatus for converting a "free-wheel liftl having parallelsupporting rails into a run-on.

lift, comprising a pair of units `adapted to be,

adjacent ends in cooperating relationship for the Y,

passage of a vehicle wheel thereover when said members are in a normalposition, means constructed and arranged to be operative when the secondnamed unit is in predetermined adjacent relationship to the first namedunit for holding the members of said pairs in normal position and forreleasing the members of each of said pairs for downward movementadjacent their adjacent ends when the second named unit moves away fromthe iirst named unit and vehicle wheels are arranged on said rampstructures, and interlocking means normally tending to hold said unitsin adjacent relationship and formed in part by one of the members of atlea'st one of said pairs of ramp members.

8. Apparatus for converting a free-wheel lift having parallel supportingrails into a run-on lift, comprising a pair of units adapted to bearranged on the supporting rails, one unit having means engageable withthe rails to prevent it from moving thereon and the other being mountedto move toward and away from the first named unit, a pair of rampstructures on the first named unit each comprising a pair of membershaving adjacent ends in cooperating relationship for the passage of avehicle wheel thereover when said members are in a normal position,means constructed and arranged to be operative when the second namedunit is in predetermined adjacent relationship to the first named unitfor holding the members of said pairs in normal position and forreleasing the members of each of said pairs for downward movementadjacent their adjacent ends when the second named unit moves away fromthe iirst named unit and vehicle wheels are arranged on said rampstructures, interlocking means normally tending to hold said units lnadjacent relationship and formed in part by one of the members of atleast one of said pairs of ramp members, and means operable when onepair of vehicle wheels passes from said first named unit to said secondnamed unit for releasing said interlocking means.

9. Apparatus for converting a free-wheel lift having parallel supportingrails into a run-on lift, comprising a pair of units adapted to bearranged on the supporting rails. one unit having means engageable withthe rails to prevent it from moving thereon and the other being mountedto move toward and away from the iirst named unit, a pair of rampstructures on the rst named unit each comprising a pair of membershaving adjacent ends in cooperating relationship for the passage of avehicle wheel thereover when said members are in a normal position.means constructed and arranged to be operative when the second namedunit is in predetermined adjacent relationship to the first named unitfor holding the members of said pairs in normal position and forreleasing the members of each of said `pairs for downward movementadjacent their adjacent ends when the second named unit moves away fromthe iirst named unit and vehicle wheels arc arranged on said rampstructures, interlocking means normally tendingto hold said units inadjacent relationship and formed in part by one of the members of atleast one of said pairs of ramp members, means operable when one pair ofvehicle wheels passes from said iirst named unit to said second namedunit `for releasing said interlocking means, and wheel chocking meanscarried by said second named unit and including a pair of movablechocking members normally' arranged in positions for the passage ofvehicle wheels thereover and movable by the vehicle wheels to chockingposition.

10. Apparatus for converting a "free-whee arranged on the supportingrails, one unit having means engageable with the rails to prevent itfrom moving thereon and the other being mounted to move toward and awayfrom the first named unit, a pair of ramp structures on the iirst namedunit each comprising a pair of members having adjacent ends incooperating relationship for the passage of a vehicle wheel thereoverwhen said members are in a normal position,

means constructed and arranged to be operative when the second namedunit is in predetermined adjacent relationshipto the rst named unit forholding the members of said pairs in normal position and for releasingthe members of each of said pairs for downward movement adjacent theiradjacent ends when the second named unit moves away from the first namedunit and vehicle wheels are arranged on said ramp structures,interlocking means normally tending to hold said units in adjacentrelationship, said other unit having wheel chocking means thereoncomprising movable wheel chocking members adapted to be moved by thepassage of vehicle wheels thereover to chocking position and tosimultaneously release said interlocking means.

11. Apparatus for converting a free-wheel lift having parallelsupporting rails, into a runon lift, comprising a pair ol units adaptedto `be arranged on the supporting rails, one unit having means engagingthe lift to prevent movement of such unit with respect to the rails andthe other unit having rollers for supporting it on the surroundingsurface for movement from the first named unit, said first named unithaving a pair of ramp structures at each side thereof, each comprising apair of members having adjacent ends for the passage of a vehicle wheelthereover onto the other unit when said members are in a normalposition, said members being pivoted at points remote from said adjacentends Whereby the latter are movable downwardly under the weight of avehicle thereon, means carried by the second named unit and engageablebeneath the member of each pair adjacent the second named unit tosupport the members oi' said pairs in their normal position i'or thepassage of one pair of vehicle wheels thereover onto the second namedunit when said units are in predetermined adjacent relationship, saidsupporting means being movable with the second named unit upon movementthereof away from the rst named unit to release the members of said pairfor downward movement at their adjacent ends upon the passage of theother vehicle wheels thereonto.

12. Apparatus for converting a free-wheel lift having parallelsupporting rails, into a runon" lift, comprising a pair of units adaptedto be arranged on the supporting rails, one unit having means engagingthe lift to prevent movement of such unit with respect to the rails andthe other unit having rollers for supporting it on the surroundingsurface for movement from the first named unit, said rstnamed unithaving a pairl of ramp structures at each side thereof, each comprisinga pair of members having adjacent ends for the passage of a vehiclewheel thereover onto the other unit when said members are in a normalposition, said members being pivoted at points remote from said adjacentends whereby the latter are movable dqwnwardly under the weight of avehicle thereon, means carried by the second named unit and engageablebeneath the member ofeach pair adjacent the second named unit tosuppor'tthe members of said pairs in their normal position for the passage ofone pair of vehicle wheels thereover onto the second named unit whensaid units are in predetermined adjacent relationship, said supportingmeans being movable with the second named unit upon movenient thereofaway from the iirst named unit to release the members of said pair fordownward movement at their adjacent ends upon the passage of the othervehicle wheels thereonto, and means normally holding said units in saidpredetermined relationship,

13. Apparatus for converting a free-wheel lift having parallelsupporting rails, into a runon lift, comprising a pair of units adaptedto beA arranged on the supporting rails, one unit having means engagingthe lift to prevent movement of such unit with respect to the rails andthe other unit having rollers for supporting it on the surroundingsurface for movement from the first named unit, said rst named unithaving a. pair of ramp structures at each side thereof. each comprisinga pair of members having adjacent ends for the passage of a vehiclewheel thereover onto the other unit when said members are in a normalposition, said members being pivoted at points remote from said adjacentends whereby the latter are movable downwardly under the weight of avehicle thereon, means carried by the second named unit and engageablebeneath the member of each pair adjacent the second named unit tosupport the members of said pairs in their normal position for thepassage of one' pair of vehicle wheels thereover onto the second namedunit when said units are in predetermined adjacent relationship, saidsupporting means being movable with the second named unit upon movementthereof away from the first named unit to release the members of saidpair for downward movement at their adjacent ends upon the passage ofthe other vehicle wheels thereonto, and means formed in part by onemember of at least one of said pairs for normally holding said units insaid predetermined adjacent relationship.

14. Apparatus for converting a free-wheel" lift having parallelsupporting rails, into a "runon lift, comprising a pair of units adaptedto be arranged on the supporting rails, one unit having means engagingthe lift to prevent movement of such unit with respect to the rails andthe other unit having rollers for supporting it on the surroundingsurface for movement from the first named unit, said iirst named unithaving a pair of ramp structures at each side thereof, each comprising apair of members having adjacent ends for the passage of a vehicle wheelthereover onto the other unit when said members are in a normalposition, said members being pivoted at points remote from said adjacentends whereby the latter are movable downwardly under the weight of avehicle thereon, means carried 'by the second named unit and engageablebeneath the member of each pair adjacent the second named unit tosupport the members of said pairs.

thereonto, and chocking means carried by saidv second named u'fiit andincluding a pivoted.

chocking member for each of a pair of vehicle wheels, said chockingmembers normally occupying a position for the passage of such vehicleWheels thereover from said pairs of members and each having a portionoperative when in such position for engaging a portion of the firstnamed structure to lock. said structures in said predetermined adjacentrelationship.

15. Apparatus for converting a free-wheel lift having parallelsupporting rails, into a runon lift, comprising a pair of units adaptedto be arranged on the supporting rails, one unit having means engagingthe lift to prevent movement of such unit with respect to the rails andthe other unit having rollers for supporting it on the surroundingsurface -for movement from the rst named unit, said iirst named unithaving a pair of ramp structures at each side thereof, each comprising apair of members having adjacent ends for the passage of a vehicle wherethereover onto the other unit when said members I are in a normalposition, said members being pivoted at points remote from said adjacentends whereby Athe latter are movable downwardly under the weight of avehicle thereon, means carried by the second named unit and engageablebeneath the member of each pair adjacent the second named unit tosupport the members of said pairs in their normal position for thepassage of one pair' of vehicle wheels thereover onto the second namedunit when said units are in predetermined adjacent relationship, saidvsupporting means being movable with the second named unit upon movementthereof away from the first named unit to release the members of saidpair for downward movement at their adjacent ends upon the passage ofthe other vehcle wheels thereonto, the member of one of said pairsadjacent the second named unit having an opening therein, and meanscarried by said second named unit and normally engageable in saidopening to prevent movement of the second named unit away from the firstnamed unit.

16. Apparatus for converting a free-wheel lift having parallelsupporting rails, into a runon lift, comprising a. pair of units adaptedto be arranged on the supporting rails, one unit having means engagingthe lift to prevent movement of such unit with respect to the rails andthe other unit having rollers for supporting it on the surroundingsurface for movement from the first named unit, said first named unithaving a pair of ramp structures at each side thereoi', each comprisinga pair of members having adjacent ends for the passage of a vehiclewheel thereover onto the other unit when said members are in a normalposition, said members being pivoted at points remote from said adjacentends whereby the latter are movable downwardly .carried by the secondnamed unit and engageable beneath the member of each pair adjacent thesecondnamed unit to support the members of said pairs in their normalposition for the passage ot one pair of vehicle wheels thereover. onto4the secondnamed unit when said units are in predetermined adjacentrelationship, said supporting means being movable with the second namedunit upon movement thereof away from the first named unit to release themembers of l said pair for downward movement at their ad- .jacent endsupon the passage of the other veable in said opening to prevent movementof the second named unit unit.

, 17. Apparatus for converting a free-wheel" lift, having parallelsupporting rails, into a runon lift, comprising a pair of units adaptedto be arranged on the supporting rails, one unit being xed to the railsand the other,having rollers supporting it for movement away from therst named unitvwhen the lift is in its lower position, a pair of platescarried bythe ilrst named unit at each side thereof, and having adjacentedges in overlapping relationship, means for supporting said-plates in anormal position forming a runway for the passage of a pair of vehiclewheels thereover onto the second named unit, and means carried by thesecond named unit and engageable beneath the plate of each pair whichhas its edge arranged beneath the edge of the other plate, whereby it issupported in position while said second named unit away from the firstnamed is in predetermined adjacent relationship to the named unit awayfrom said first named unitA whereby said plates act as chocking meansfor the other wheels of the vehicle.

18. Apparatus lfor converting a free-wheel lift, having parallelsupporting rails, into a runon lift, comprising a pair of units adaptedto be arranged on the supporting rails. one unit being fixed to therails and the other having rollers supporting it for movement away fromthe first named unit when the lift is in its lower position, a pair ofplates carried by the rst named unit' at each side thereof, and havingadjacent edges in overlapping relationship, means for supporting saidplates in a normal position forming a runway for the passage of a pairof vehicle wheels lthereover, onto the second named unit, and

means carried .by the second named unit and engageable beneath the plateof each pair which has its edge arranged beneath the edge of the otherplate, whereby it is supported in position while said second named unitis in predetermined adjacent relationship to the rst named unit, theplates of each pair being pivoted at points remote from the overlappingedges thereof whereby they are free to swing downwardly un-V der theweight of the vehicle when the other wheels thereof move into positionson said plates and said second named unit moves away from said firstnamed unit.

19. Apparatus for converting a free-wheel lift, having parallelsupporting rails, into afrunon lift, comprising a pair of lunits onehaving means for fixing it to said rails and the other being supportedfor4 movement away from said first named unit, said first named unithaving a pair of ramp structures for the passage thereover of vehiclewheels. each ramp structure having a section thereof pivoted at a pointremote from theentering end thereof whereby it is free to swingdownwardly by gravity when the lift is elevated, to assume a position atrelatively slight angle lto the vertical, and a wheel carried by thefree endof each pivoted section engageable with the 'surrounding surfaceto be moved upwardly relative to the vehicle lift when the latter islowered.

20. Apparatus for converting a "free-wheel lift, having parallelsupporting rails, into a runon lift,4 comprising a pair of units onehaving means for xing it to said rails and the other being supported formovement away from said iirst named unit, said rst named unit having apair of ramp structures for the passage thereover of vehicle wheels,each ramp structure having a section thereof pivoted at a point remotefrom the entering end thereof whereby itis free to swing downwardly bygravity when the lift is i lift, having parallel supporting rails, intoa runon lift, comprising a pair of units adapted to be arranged on thesupporting rails, one for supporting the front vehicle wheels and theother for supporting the rear vehicle wheels. one of said units having apair of ramp structures each comprising a pair of members havingadjacent en ds in cooperative relationship and normally positioned forthe passage of a vehicle wheel thereover onto the other unit, saidmembers being pivoted at points remote from said cooperating endswhereby the latter are movable downwardly under the weight of a vehiclethereon under predetermined conditions to chock the vehicle wheelthereon, and an entrance ramp normally forming substantially acontinuation of the ramp structure of each pair and pivoted theretoremote from the front wheel supporting unit for downward swingingmovement when the lift is elevated.

22. Apparatus for converting a free-wheel lift, having parallelsupporting rails, into a runon lift, comprising a pair offunits adaptedto be arranged on the supporting rails, one for supporting the frontvehicle wheels and the other for supporting the rear vehicle wheels, oneof said units having a pair of ramp structures each comprising a pair ofmembers having adjacent ends in cooperative relationship and normallypositioned for the passage of a vehicle wheel thereover onto the otherunit, said members being pivoted at points remote 'from said cooperatingends whereby the latter are movable downwardly under the weight` of avehicle thereon under predetermined conditions to chock the vehiclewheel thereon, and an entrance ramp normally forming substantially acontinuation of the ramp vstructure of each pair and pivoted theretoremote from the `front wheel supporting unit for downward swingingmovement when the lift is elevated, the free end of each entrance ramphaving afwheel thereon engageable with the surrounding surface to besupported thereby during downward movement of the lift to be restored toits normal position.

23. Apparatus for converting a free-wheell lift, having parallelsupporting rails, into a runon lift, comprising a pair of units adaptedto be arranged on the supporting rails, one for supporting the frontvehicle wheels and the other for supporting the rear vehicle wheels, oneof said units having a pair of ramp structures each structure of eachpair and pivoted thereto remote from the front wheel supporting unitVfor downward swinging movement when the lift is elevated, the free endofl each entrance` ramp having a wheel thereon engageable with thesurrounding surface to be supported thereby during downward movement ofthe lift to be restored to its normal position, and means for lim'-iting downward swinging movement of each entrance ramp to a positionoffset toward the entrance end of the lift from a vertical plane passingthrough the pivot axis of 4such entrance ramp.

24. Apparatus for converting a free-wheel lift, having parallelsupporting rails, into a .jrunon lift, comprising va pair of unitsadapted to be arranged on'the supporting rails, one of said units beingimmovable along the rails and the other having wheels engaging thesurrounding surface whereby it is movable toward and away from' thefirst named unit, said wheels having deformable cushion rims, said unitshaving cooperating means providing for the passage of a pair of vehiclewheels over the rst named unit onto th second' named unit whereupon thelatter is movable away from the first named unit, and means forpositively bodily supporting the end of the second named unit adjacentthe first named unit when said units are in predetermined adjacentrelationship.

25. Apparatus for converting a free-wheel lift, having parallelsupporting rails, into a runl on lift, comprising a pair of unitsadapted to be arranged on the supporting rails, one of said units beingimmovable along the rails and the other having wheels engaging thesurrounding surface whereby it is movable toward and away from the firstnamed unit, said wheels having deformable cushion rims, said unitshaving co- A operating means providing for the passage of a pair ofvehicle wheels over the first named unit .onto the second named unitwhereupon the latter is movable away from the` irst named unit, meansfor locking said second named unit 4in adjacent predeterminedrelationship to'said rst vnamed unit, and means for positively bodilysupporting the end of the second ynamed unit adjacent the first namedunit when said .units are in predetermined adjacent relationship.

26. Apparatus for converting a @ree-wheel lift, having parallelsupporting rails, into a run' on lift, comprising a pair of unitsadapted to be arranged on. the supporting rails, one of said /unitsbeing immovable along the railsand the other having wheels engagingthesurrounding surface whereby it is movable toward and away from the firstnamedunit,A said wheels having deformable cushion rims, said unitshaving coover to said lsecond named unit, said second,

named unit having a portion at the end thereof adjacent said rst namedunit engageable with the latter to positively bodily support such end ofsaid second named unit when said units are in said predeterminedadjacent relationship.

27. Apparatus for converting a free-wheel lift, having parallelsupporting rails, into a runon lift, comprising a pair of units adaptedto be arranged on the supporting rails, one of said units beingimmovable along the rails and the other` being movable therealong, saidmovable unit comprising a frame and supporting wheels therefor havingdeformable cushion rims, ysaid units having cooperating means providingfor the passage of a pair of vehicle wheels over the immovable unit ontothe movable unit whereupon the latter is movable awayv from theimmovable unit, means for locking said movable unit with respect to saidimmovable unit with the units in adjacent predetermined relationship,and means for poistively preventing downward movement of the end of saidframe adjacent said immovable unit when said units are in said adjacentpredetermined relationship.

PHILIP J. KROLL.

